Materials with good stretchability and elasticity are used to manufacture a variety of nonwoven disposable articles in addition to durable articles including incontinence pads, disposable diapers, training pants, clothing, undergarments, sports apparel, automotive trim, weather-stripping, gaskets, and furniture upholstery. For clothing, stretchability and elasticity are performance attributes that allow the materials to provide a closely conforming fit to the body of the wearer.
While numerous materials are known to exhibit excellent stress-strain properties and elasticity at room temperatures, it is often desirable for elastic materials to provide a conforming or secure fit during repeated use, during extensions and retractions at elevated or depressed temperatures, or in automobile interiors during summer months. Elasticity at elevated temperatures is also important for maintaining tight tolerances throughout temperature cycles. In particular, elastic materials used for repeated wear clothing or garments must maintain their integrity and elastic performance after laundering.
Spandex, a segmented polyurethane urea elastic material, is currently used in various durable fabrics. However, articles made from spandex can lose integrity, shape, and elastic properties when subjected to elevated temperatures and polyurethane-based components are costly and do not readily adhere to olefinic adhesives. U.S. Pat. No. 8,358,291 discloses a method of making an elastomeric article from a propylene-based material having good thermal resistance, resistance, stretchability, and elasticity.
To prepare nonwoven articles, hot melt adhesive (HMA) compositions are generally used to adhere one or more layers of film and/or fabric. For such articles, HMA compositions are sought that provide a desired combination of physical properties such as stable adhesion over time indicative of broad application temperature ranges, and machine coatability. Exemplary base polymer compositions and methods of making polymer compositions for HMA applications are disclosed in U.S. Pat. Nos. 7,294,681 and 7,524,910. Various polymers described in these patents and/or produced by the methods disclosed in these patents have been sold by ExxonMobil Chemical Company as LINXAR™ polymers. International Publication No. WO2013/134038 discloses a method for producing a novel polymer blend having at least two different propylene-based polymers produced in parallel reactors. The multi-modal polymer blend has a Mw of about 10,000 g/mol to about 150,000 g/mol.
Although many different types of polymers are known and have been used in HMA formulations, such as those using spandex or Lycra®, nonwoven articles are often prepared using adhesive compositions having high application temperatures, around the order of greater than 150° C. For olefin-based elastomers, the integrity of the elastomeric composition can be compromised when adhesives are applied at temperatures above 150° C. Accordingly, there is a need for an adhesive composition that can be applied at an application temperature of lower than 150° C. to bind one or more elastomeric articles for manufacturing of a variety of nonwoven applications.